JP5935586B2 - Manufacturing method of semiconductor laminated unit - Google Patents

Description

The present invention relates to a method of manufacturing a semiconductor laminate unit in which a plurality of semiconductor modules and a plurality of cooling plates of matches and semiconductor elements are integrated.

  A voltage converter that boosts or lowers a voltage or an inverter that supplies an alternating current to an induction motor includes a large number of semiconductor elements. A typical semiconductor element used is a transistor used as a switching element. As the transistor of the switching element, an IGBT or a MOSFET is typically used. The semiconductor element generates heat according to the magnitude of the flowing current. An electric vehicle travel motor has a large output. Therefore, a semiconductor element used in a drive system of an electric vehicle generates a large amount of heat.

  Patent Documents 1 and 2 disclose a cooling device that efficiently cools a semiconductor element that generates a large amount of heat, and is a compact cooling device. In any case, a semiconductor element is housed in a flat plate (card type) semiconductor module, and a plurality of semiconductor modules and a plurality of flat plate cooling plates through which a coolant flows are alternately stacked. Such a laminate is referred to herein as a laminate structure. Moreover, the laminated structure supported by the housing may be referred to as a semiconductor laminated unit. As an example, the semiconductor laminated unit is mounted on a power control unit of an electric vehicle. The “power control unit” means a controller including an inverter circuit, a voltage converter, and other peripheral devices necessary for driving the motor.

  In the semiconductor laminated unit described in the patent document, adjacent cooling plates cool the semiconductor module from both sides. In order to cool the semiconductor module efficiently, it is better that the cooling plate and the semiconductor module are in close contact with each other. Therefore, the stacked structure is supported while receiving a load in the stacking direction. In the technique of Patent Document 1, a load is applied to the laminated structure from both sides in the lamination direction using U-shaped leaf springs that open at intervals of about the length in the lamination direction of the laminated structure. A leaf spring is provided for each row of stacked semiconductor modules. In the technique of Patent Document 2, a semiconductor multilayer unit and a housing having a relationship in which the linear expansion coefficient in the stacking direction of the semiconductor multilayer unit is larger than the linear expansion coefficient of the housing are prepared and lower than the operating temperature of the semiconductor multilayer unit. Assemble the semiconductor multilayer unit to the housing in a temperature atmosphere. Note that in a temperature atmosphere lower than the operating temperature, the semiconductor multilayer unit contracts and its length becomes shorter than the inner width of the housing. Due to the difference in linear expansion coefficient, a housing with low expansion pressurizes a semiconductor multilayer unit with high expansion at the operating temperature.

JP 2005-228877 A JP 2009-21404 A

  The laminated structure is configured by connecting adjacent cooling plates with two connecting pipes, sandwiching a semiconductor module between the cooling plates, and stacking them in a plurality of stages. The connection length of the connection pipe and the thickness of the semiconductor module are not necessarily constant and include errors. For this reason, as the number of stacking stages increases, the accumulation of this error causes variation in the stacking direction length of the stacked structure, which is managed within a predetermined tolerance range.

  In the technique of Patent Document 1, a load is applied by a leaf spring for each row of stacked semiconductor modules. Therefore, it is necessary to adjust the leaf springs so as to absorb the tolerance of the laminated structure for each row of semiconductor modules. In the technique of Patent Document 2, the casing pressurizes the semiconductor stacked unit in a relative relationship due to the difference in linear expansion coefficient. However, since the stacked structure expands uniformly regardless of the size of the tolerance, there is a tolerance. It expands including its tolerance. That is, the technique of Patent Document 2 is not suitable for absorbing such tolerances. This specification was created in view of the above problems. The present specification provides a technique for suppressing a decrease in cooling performance due to a tolerance in a stacking direction length of a stacked structure in a semiconductor stacked unit in which a plurality of semiconductor modules and a plurality of cooling plates are stacked alternately. .

  One aspect of the semiconductor laminated unit disclosed in this specification is as follows. In the laminated structure, a plurality of semiconductor modules containing semiconductor elements and a plurality of cooling plates are alternately laminated. The housing is composed of an elastically deformable member. Further, the housing has a bottom surface, and has two walls that rise from the bottom surface in parallel at an interval narrower than the length of the stacked structure in the stacking direction. The wall may be a side wall of the housing or a wall standing on the bottom plate in the housing. A laminated structure is sandwiched between the two walls.

  As described above, the casing is formed of an elastically deformable member. The casing is particularly made so that the elastic modulus in the bending direction of the bottom plate is lower than the elastic modulus in the bending direction of the wall. Therefore, in the above-mentioned semiconductor laminated unit, the laminated structure is inserted with the laminated direction facing the wall surface between the walls warped so that the interval between the two walls is widened, and the warped wall is returned. It can be assembled by sandwiching the laminated structure.

  In the above structure, since the casing itself is elastically deformed, even if the laminated structure sandwiched between the two walls has a tolerance for the length in the lamination direction, the casing is matched to the tolerance of each laminated structure. The body deforms. Therefore, a pressurizing force due to the elastic restoring force of the deformed casing is applied to the laminated structure sandwiched between the walls. The housing adheres the cooling plate and the semiconductor module while absorbing such tolerances. That is, a decrease in cooling performance due to the tolerance in the stacking direction length of the stacked structure is suppressed. Further, since the laminated structure is pressed by the casing itself, a pressing member such as a leaf spring is not required, which contributes to reduction in the number of parts and cost reduction.

  As a further improvement of the semiconductor stacked unit disclosed in this specification, a reinforcing structure may be provided on the contact surface of the wall with which the stacking direction end of the stacked structure contacts or on the back side thereof. By having the reinforcing structure, the elastic modulus in the bending direction of the wall can be made higher than the elastic modulus in the bending direction of the bottom plate. The reinforcement structure ensures the rigidity of the wall at the contact surface with which the end portion in the stacking direction of the laminated structure abuts, so that the elasticity of the wall is increased and the pressure applied to the laminated structure is further increased. The reinforcing structure is preferably a rib extending in the vertical direction of the wall. The rigidity in the direction in which the wall warps is increased by elastic deformation, and the surface area is increased by the shape of the rib, so that the heat dissipation function by the housing is also improved. The vertical direction of the wall corresponds to the direction in which the wall rises from the bottom surface.

Herein provides a novel process for producing a semiconductor laminate unit that describes above. The method includes a pressing step of pressing the stacked structure from both sides in the stacking direction so that the alternately stacked semiconductor modules and the cooling plate are in close contact with each other, and the casing so that the interval between the two walls is widened. Inserted between the loading step of applying a load to both side walls, the insertion step of inserting the laminated structure in which the semiconductor module and the cooling plate are in close contact with each other in the pressurization step, between the two walls that are widened in the loading step, and the insertion step A releasing step of leaving the laminated structure between the two walls and removing the load on both side walls by the loading step.

  Details and further improvements of the technology disclosed in this specification will be described in the following “DETAILED DESCRIPTION”.

It is a perspective view of the semiconductor lamination unit of an example. It is the II-II sectional view taken on the line of the semiconductor laminated unit of an Example shown in FIG. It is the III-III sectional view taken on the line shown in FIG. 2 of the semiconductor lamination | stacking unit of an Example. It is sectional drawing explaining the manufacturing process of a semiconductor lamination unit (1). It is sectional drawing explaining the manufacturing process of a semiconductor lamination unit (2). It is sectional drawing of the semiconductor lamination | stacking unit of a modification (1). It is sectional drawing of the semiconductor lamination | stacking unit of a modification (2). It is sectional drawing of the semiconductor lamination | stacking unit of a modification (3). It is sectional drawing of the semiconductor laminated unit of a modification (4).

  The semiconductor laminated unit 2 of an Example is demonstrated with reference to drawings. FIG. 1 is a perspective view of the semiconductor multilayer unit 2, FIG. 2 is a cross-sectional view taken along the line II-II shown in FIG. 1 (cross-sectional view taken along the XZ plane and viewed from the Y direction), FIG. III-III sectional view (sectional view cut from the XY plane and viewed from the anti-Z direction) is shown respectively.

  The semiconductor laminated unit 2 of the embodiment is a component built in a power control unit (PCU) of an electric vehicle, and cools a plurality of semiconductor elements used for an inverter circuit and semiconductor elements used for a voltage converter in an integrated manner. Device. The semiconductor element is a switching element (and a diode), and is typically an IGBT. The semiconductor multilayer unit 2 includes a multilayer structure 10 and a housing 15 as main components.

  The laminated structure 10 is obtained by alternately laminating a plurality of flat plate type semiconductor modules 12 and a plurality of flat plate type cooling plates 3a to 3h. The semiconductor module 12 is obtained by molding an IGBT (switching element) and a diode (semiconductor element) with a resin. As is well known, the inverter circuit has a circuit configuration in which three sets of series connection of two switching circuits (an antiparallel circuit of IGBT and diode) are connected in parallel. In addition, the switching circuit built in the semiconductor module 12 is also used for a voltage converter that changes the voltage. In addition, although the semiconductor module 12 is provided with the terminal connected with an internal semiconductor element, the illustration is abbreviate | omitted.

  The cooling plates 3a to 3h are hollow inside (see FIGS. 2 and 3), and have through holes at both ends in the longitudinal direction (Y-axis direction in the drawing). A short connecting pipe 13 is connected to the through hole. Adjacent cooling plates are connected by the two connecting pipes 13. A refrigerant supply pipe 4 and a refrigerant discharge pipe 5 are connected to the cooling plate 3 a located at one end of the laminated structure 10. When the laminated structure 10 is viewed from the lamination direction (X-axis direction in the figure), the refrigerant supply pipe 4 and one connection pipe 13 of each cooling plate appear to overlap each other, and the refrigerant discharge pipe 5 and the other connection pipe 13 are seen. Appear to overlap. That is, both the refrigerant supply pipe 4 and the refrigerant discharge pipe 5 extend along the lamination direction of the laminated structure 10.

  The refrigerant is supplied from a refrigerant tank (not shown) through a refrigerant discharge tube. The refrigerant reaches all the cooling plates via the refrigerant supply pipe 4 and the connection pipe 13 aligned with the refrigerant supply pipe 4, and the semiconductor module 12 that is in contact with the cooling plates 3a to 3h while flowing from the one end to the other end. Cooling. The refrigerant that has passed through the cooling plates 3a to 3h is returned to the refrigerant tank through the refrigerant discharge pipe 5 and the connection pipe 13 aligned with the refrigerant discharge pipe 5, and further through the refrigerant discharge tube.

  The cooling plates 3a to 3h, the connecting pipe 13, the refrigerant supply pipe 4, and the refrigerant discharge pipe 5 are made of aluminum having a high thermal conductivity. In some cases, fins for enhancing the cooling capacity are incorporated in the cooling plates 3a to 3h.

  The housing 15 is an open rectangular box having a bottom that accommodates the laminated structure 10 therein, and is configured of a member that can be elastically deformed. Typically, the housing 15 is made of aluminum. When the side from which the refrigerant supply pipe 4 and the refrigerant discharge pipe 5 protrude is the front direction, the housing 15 has a front wall 15a having a U-shaped groove 17 through which these pipes can penetrate, and a rear wall 15b opposite to the front wall 15a. And a right wall 15c and a left wall 15d located on both sides thereof, and a bottom plate 15e on which these four walls rise on a rectangular bottom formed by these.

  Among these walls, the interval between the front wall 15a and the rear wall 15b positioned before and after the stacked structure 10 in the stacking direction is set to be narrower than the natural length of the stacked structure 10 in the stacking direction. In addition, natural length means the full length in the state which does not receive a load in the lamination direction. Further, the bottom plate 15e connecting these two walls is set so that the elastic modulus in the bending direction is lower than the elastic modulus in the bending direction of the front wall 15a and the rear wall 15b.

  For this reason, by applying a force to warp the front wall 15a and the rear wall 15b outward, the bottom plate 15e is deformed more greatly than the front wall 15a and the rear wall 15b, and the front wall 15a and the rear wall 15b are deformed. Spacing increases. As a result, the space between the two walls, which has been narrowed so far, expands larger than the natural length in the stacking direction of the stacked structure 10, so that the stacked structure 10 can be held between the front wall 15a and the rear wall 15b. . As shown in FIG. 2, the laminated structure 10 sandwiched between both walls is held in a state of floating from the bottom plate 15 e and accommodated in the housing 15.

  The front wall 15a and the rear wall 15b are provided with a flange 16 extending outward in a direction substantially parallel to the bottom plate 15e in order to make it easy to apply pressure to widen the gap between the front wall 15a and the rear wall 15b. Except for a part of 15a, it is formed over almost the entire open end. Further, a thickened portion 21 is formed on the rear wall 15b on the end in the stacking direction of the stacked structure 10, that is, on the back side where the cooling plate 3h comes into contact.

  The thickened portion 21 functions as a reinforcing structure for the rear wall 15b. As shown in FIG. 3, the thickened portion 21 is provided in a range that overlaps with the stacked position of the semiconductor modules 12 sandwiched between the cooling plates 3 a to 3 h. In other words, the thickened portion 21 is provided in the rear wall 15b in a range that overlaps the semiconductor module 12 in the stacking direction of the stacked structure 10. The thickened portion 21 is a gradually changing thickness portion (convex portion) formed in a raised ridge shape with a gradually increasing thickness as compared with other portions of the rear wall 15b. In this embodiment, the rear wall It is provided in two places along the height direction of 15b.

  By providing such a thickened portion 21 on the rear wall 15b holding the laminated structure 10, the elastic modulus in the bending direction of the rear wall 15b described above becomes higher than the elastic modulus in the bending direction of the bottom plate 15e. . Therefore, high rigidity is ensured for the rear wall 15b at the contact surface with which the cooling plate 3h of the laminated structure 10 abuts, so that the elasticity of the rear wall 15b is increased and the pressure applied to the laminated structure 10 is further increased.

  Next, an assembly method (manufacturing method) of the semiconductor multilayer unit 2 will be described with reference to FIGS. 4 and 5. 4 and 5 are cross-sectional views illustrating the manufacturing process. These figures correspond to the sectional view taken along the line II-II in FIG. 1, as in FIG.

  First, in the process of assembling the laminated structure 10 (FIG. 4A), the semiconductor module 12 is inserted into the gaps between the cooling plates 3a to 3h in which the refrigerant supply pipe 4, the refrigerant discharge pipe 5, and the connection pipe 13 are assembled. The The cooling plates 3a to 3h are assembled so that each gap is slightly wider than the thickness of the semiconductor module 12, and from one end to the other end in the stacking direction, for example, the cooling plate 3a to the cooling plate The semiconductor modules 12 are inserted in order toward 3h.

  When the semiconductor module 12 is inserted and the stacked structure 10 is completed, the process proceeds to a pressurizing step (FIG. 4B) that compresses the stacked structure 10 from both sides in the stacking direction. This pressurizing step is performed in order to eliminate the gap generated between each of the cooling plates 3a to 3h and the semiconductor module 12 inserted between them, and the predetermined pressure Fx is a laminated structure. Added from both sides of body 10.

  In parallel with or before or after the pressurizing step, a load is applied to the front wall 15a and the rear wall 15b of the housing 15 by the loading step (FIG. 4C). At this time, the housing 15 is not placed on a flat surface, but a support portion 31 that extends in a bar shape in the left-right direction (Y-axis direction in the drawing) of the bottom plate 15e of the placed housing 15 is a bottom plate 15e. Are placed on two support portions 31 so as to be positioned at two locations so as to sandwich the center portion on the back side in the front-rear direction (X-axis direction in the figure) at a predetermined distance. The predetermined distance is set to, for example, 1/3 of the length in the front-rear direction of the bottom plate 15e.

  In the loading process, since such a support portion 31 exists on the back side of the bottom plate 15e of the housing 15, the flanges 16 of the front wall 15a and the rear wall 15b are provided from above the housing 15 placed on the support portion 31. When the load Fz is applied, the bottom plate 15e is elastically deformed so as to warp the support portion 31 with respect to the fulcrum, and both the front wall 15a and the rear wall 15b are elastic so that they are inclined toward the outside (thin arrows in the figure). Deform. At this time, even if the front wall 15a and the rear wall 15b are deformed to be warped, the elastic deformation amount is smaller than that of the bottom plate 15e due to the difference in elastic modulus.

  By the loading process, both the front wall 15a and the rear wall 15b of the housing 15 are opened outward. Therefore, the interval between the front wall 15a and the rear wall 15b is wider than the length in the stacking direction of the stacked structure 10 after being compressed in the pressurizing step, and the stacked structure 10 can be received. Therefore, in the insertion step (FIG. 5A), the compressed laminated structure 10 is inserted from above the housing 15 that is undergoing elastic deformation. The insertion process is completed by securing a position immediately before the stacked structure 10 contacts the bottom plate 15e of the housing 15 or a predetermined interval (FIG. 5B). When the position of the laminated structure 10 in the depth direction within the housing 15 is determined, the load Fz is released in a state where the laminated structure 10 remains in the housing 15 by the release process (FIG. 5C). . As a result, the bottom plate 15e, the front wall 15a, and the rear wall 15b return to their original shapes, so that the laminated structure 10 in the housing 15 is held between the front wall 15a and the rear wall 15b and compressed. .

  In the semiconductor laminated unit 2 described above, the housing 15 itself is elastically deformed. Therefore, even if the laminated structure 10 sandwiched between the front wall 15a and the rear wall 15b has a tolerance with respect to the length in the lamination direction, the casing 15 is deformed according to the individual tolerance of the laminated structure 10. Thus, a pressing force is applied to the sandwiched laminated structure 10 by the elasticity of the front wall 15a and the rear wall 15b. Therefore, the cooling plates 3a to 3h and the semiconductor module 12 can be brought into close contact with each other while absorbing such individual tolerances, so that the cooling performance is reduced due to the tolerance in the stacking direction length of the stacked structure 10. It is suppressed. Further, since the laminated structure 10 is pressed by the casing 15 itself, a pressing member such as a leaf spring is not required, which contributes to a reduction in the number of parts and cost.

  In the manufacturing method described above, the load and support of the laminated structure 10 are simultaneously performed by the both walls 15a and 15b of the housing 15. Therefore, the manufacturing process can be simplified and the manufacturing cost can be suppressed.

  In addition, the modification shown in FIGS. 6-9 is mentioned as the further improvement of the housing | casing 15. FIG. As shown in FIG. 6, in the front-rear direction (X-axis direction in the drawing) end of the bottom plate 15e, that is, in the vicinity of the connection portion with the front wall 15a and the rear wall 15b, the left-right direction (Y-axis direction in the drawing). A concave groove (vent shape) 15f is provided. Thereby, since the spring property of the front wall 15a and the rear wall 15b with respect to the baseplate 15e further improves, the baseplate 15e becomes easy to deform | transform.

  Various variations of the reinforcing structure provided in the housing 15 are assumed. As shown in FIG. 7, instead of the thickened portion 21 provided on the rear wall 15b, a rib 22 (see FIG. 7A) or a bead 23 (see FIG. 7B) may be used. The ribs 22 and the beads 23 are provided in a range overlapping with the stacked positions of the semiconductor modules 12 similarly to the thickened portion 21 and are formed to extend in the height (rise) direction of the rear wall 15b. The rib 22 is a continuous convex shape that is formed integrally with the rear wall 15b and extends in a linear shape. Further, the bead 23 is formed by continuous back and forth unevenness extending linearly by the rear wall 15b itself. The bead 23 is formed by overlay welding, for example. Or the bead 23 is shape | molded simultaneously when the housing | casing 15 is press-molded.

  Also with the ribs 22 and the beads 23, the elastic modulus in the bending direction of the rear wall 15b becomes higher than the elastic modulus in the bending direction of the bottom plate 15e, similarly to the thickened portion 21, so that the elasticity of the rear wall 15b is increased and laminated. The pressure applied to the structure 10 is further increased. Further, since the surface area increases when the rib 22 or the bead 23 is formed, compared with the case where the thickened portion 21 is formed on the rear wall 15b, the heat dissipation function by the housing 15 is also improved.

  Further, such a reinforcing structure may be provided on the front side of the rear wall 15b with which the cooling plate 3h abuts, that is, in the abutting range of the cooling plate 3h on the rear wall 15b. Furthermore, like the bead 23 shown to FIG. 7 (B), you may provide in both surfaces of the rear wall 15b with which the cooling plate 3h contact | abuts.

  Further, as shown in FIG. 8, separately from the front wall 15 a and the rear wall 15 b, pressure walls 18 and 19 rising from the housing 15 may be provided and used as a wall for sandwiching the laminated structure 10. For example, in the gap provided between the cooling plate 3h and the rear wall 15b, the pressure wall that faces the front wall 15a and whose distance from the front wall 15a is set narrower than the length of the laminated structure 10 in the stacking direction. 18 is formed to rise from the bottom plate 15e (see FIG. 8A). In addition, a pressure wall that is opposed to the rear wall 15b and that is spaced from the rear wall 15b in a gap provided between the front wall 15a and the cooling plate 3a is set to be narrower than the length of the laminated structure 10 in the stacking direction. 19 is formed so as to rise from the bottom plate 15e (see FIG. 8B). Similar to the rear wall 15b and the front wall 15a, these pressure walls 18 and 19 are set so that the elastic modulus of bending in the height (rise) direction is higher than the elastic modulus of the bottom plate 15e. Moreover, as shown to FIG. 9 (A), you may comprise so that both such pressurization walls 18 and 19 may be provided and the laminated structure 10 may be pinched and hold | maintained among these.

  As a result, the pressure wall 18 is warped toward the rear wall 15b to widen the space between the front wall 15a and the pressure wall 18, and the pressure wall 19 is warped toward the front wall 15a. The space between the pressure wall 19 and the rear wall 15b expands. When both walls are pressure walls, the space between the pressure walls 18 and 19 expands. For this reason, it becomes possible to hold and hold the laminated structure 10 at these widened intervals like the above-described front wall 15a and rear wall 15b. Similar to the rear wall 15b, the pressure walls 18 and 19 are provided with a thickened portion (or rib) extending in the height (rise) direction in a range overlapping with the stacking position of the semiconductor modules 12, so that these elasticities can be obtained. The rate is further increased than that of the bottom plate 15e.

  In addition, the wall which these pressurization walls 18 and 19 oppose is the block shape comprised, for example, as shown in FIG.9 (B), where the thickness of a part of the front wall 15a or the rear wall 15b is thickened. The block wall 15g may be used. In this case, since the block wall 15g itself hardly undergoes elastic deformation, the bottom plate 15e mainly undergoes elastic deformation, and the distance between the two can be further increased.

  Points to be noted for the technology described in the embodiments will be described. In the embodiment, since the semiconductor modules 12 are stacked in two rows, the thickened portion 21, the ribs 22, and the beads 23 are provided as reinforcing structures at two positions in a range overlapping with the stacking positions of the semiconductor modules 12. It was. In this manner, a reinforcing structure may be provided for each row in which the semiconductor modules 12 are stacked, or a reinforcing structure may be provided continuously so as to span all rows. The front wall 15a corresponds to an example of one side wall, and the rear wall 15b corresponds to an example of the other side wall. The thickened portion 21, the rib 22 and the bead 23 correspond to an example of a reinforcing structure.

  Specific examples of the present invention have been described in detail above, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. Further, the technical elements described in the present specification or drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Moreover, the technique illustrated in this specification or the drawings achieves a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

2: Semiconductor laminated unit 3a-3h: Cooling plate 4: Refrigerant supply pipe 5: Refrigerant discharge pipe 10: Laminated structure 12: Semiconductor module 13: Connection pipe 15: Housing 15a: Front wall 15b: Rear wall 15c: Right wall 15d: left wall 15e: bottom plate 16: flange 18, 19: pressure wall 21: thickened portion 22: rib 23: bead

Claims (4)

A laminated structure in which a plurality of semiconductor modules containing semiconductor elements and a plurality of cooling plates are alternately laminated, and a casing having a bottom surface made of an elastically deformable member, wherein the laminated structure is laminated and a housing having two walls rising from the bottom surface in parallel with an interval smaller than the length of the direction, a manufacturing method of a semi-conductor laminate unit the laminated structure that is sandwiched between the two walls Because
A pressing step of pressing the stacked structure from both sides in the stacking direction so that the semiconductor modules and the cooling plate stacked alternately are in close contact with each other;
A loading step of applying a load to both side walls of the housing so that the interval between the two walls is widened;
An insertion step of inserting the laminated structure in which the semiconductor module and the cooling plate are in close contact with each other in the pressurization step between the two walls whose interval is expanded in the load step;
A releasing step of removing the load on both side walls by the loading step, leaving the laminated structure inserted in the insertion step between the two walls;
A manufacturing method comprising: The process according to claim 1, characterized in that the stacking direction end portion of the laminated structure a wall surface of the wall to the abutment surface or back side thereof abutting, the reinforcing structure is provided. The manufacturing method according to claim 2, wherein the reinforcing structure of the wall is a rib extending in a vertical direction of the wall. The two walls The production method according to claim 1, characterized in that the opposite side walls of the housing.

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